1. Nuclear Fission and Fusion 18.2

2. INTRODUCTION  1939-Hahn/Strassman- Tried to add neutrons to Uranium- nucleus split- FISSION!!

3. Nuclear Forces  Unstable nuclei-decay-emit radiation  Carbon 12-stable  Carbon 14-unstable  Depends on the forces b/t protons/neutrons  =STRONG NUCLEAR FORCE  Stable=attractive forces stronger than repulsion (proton to proton)

4. Nucleus Overload  Too many neutrons= unstable= critical mass  Any element with protons over 83 are unstable

5. Nuclear Fission DDDDivision of a nuclei= heavierSmaller CCCCreates lg. amounts of energy EEEE=mc2 Energy=mass x (speed of light)2 CCCC= 3.0 x 10 8 ( ( HUGE ) NNNNuclear Chain Reaction  - -----

7. Fission cont….  Uranium-235= Atomic Bomb  Critical mass is reached-undergo fission

9. Nuclear Fusion NNNNuclei combining smallerheavier HHHHUGE HUGE amount of energy needed to combine protons (same charge) SSSSun/Stars H-nuclei  He- nuclei